The ChatGPT Apps SDK has a steep learning curve, specially OAuth, where you're the provider and ChatGPT is the client (not the other way around). This can trip you up easily.

This skill teaches Claude Code how to build ChatGPT apps correctly:

  - MCP server setup (Node.js/Python)
  - OAuth with PKCE and Dynamic Client Registration
  - Widget development with window.openai API
  - 20+ gotchas with fixes

How to install it:

npx skills add https://github.com/vdel26/skills``

GitHub:

https://github.com/vdel26/skills

Would love feedback on missing gotchas people have hit while building ChatGPT / MCP Apps.